Aluminum siding corners

These corner pieces CONSTANTLY come off so to get ready for a refi appraisal I'm gonna nail most of these on for good.
I'm planning to use a nailer but am not sure what nails to use.
Shingle nail? Roofing nail?
Do either come in packs for nailers?

Aluminum siding corners

May be the small corners that used to be used long ago on Masonite type siding.
If you use use trim nails. There sold in the siding area. There going to be aluminum. The better ones are stainless steel but for some reason the box stores in most cases do not carry them.